* {
    margin: 0;
    border: 0;
    box-sizing: border-box;
}
 a{
    text-decoration: none;
    color: #333;
 }
 li {
    list-style: none;
 }
body,html {
    width: 100%;
    height: 100%;
    background-color: #f5f5f5;
}